SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2328a01702a321bea0d5545aa6f094502690198bebf0f9c2f7dedbda8d10df5' 
  AND token = 'ghfj5S0C0Ut4ik4vhDFLCutIbg03sBFSSClYOQlSHw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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