SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc73d2d7ae7ec7735c496116f02d3a9e2712d3eda59b2135ed0dbd21423b3dfc' 
  AND token = 'QC5m1IaiM3+fTiv/0saHazmHaKmK4OImdwuPxhg192M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}