SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b70588897692574488e5b0754cf80e634c5a717c772540322007636f27078369' 
  AND token = 'zn/Wegd6MZfmSG+DLs7JML9/Rhd8Pbs/2mNfpuESEfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}