SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '811a5bde34732736dc48333e835eab9cbe4c0f451b26ee8aadac37a3a052e732' 
  AND token = 'Dy6IZ2nvvSnimSDk+99r0EgNQsHxSi81DVUDPcTgE8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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