SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4101bb05c15a1483b250ecad9d57fc247a99e74e75916b2d3acadc2c043df060' 
  AND token = 'r4HXJZV1DYHfs2/MiYrEOYQS4DokAdbKtstHTZpwfRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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