SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85b27419cba731eade7e4aaa722e1bdda1dfca6a3d0b0e6d867f1b0cc4dda268' 
  AND token = 'iydZT74OCnBkrDePBHIoyhHq2Ssxsukm2Sf65Jz3o0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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