SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3822339b0f11ddd51c23d07a66aa4c978d9d5ffbf0d4776dfcd48ae17bf30fa' 
  AND token = 'y70jJIaIfOPVeq1JjAyL80goaKCL672Gyb0/Lqhei2I=' 
  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"
    }
  }
}