SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '088357bceaacd6ee448b693cc1133f70b3aa8408b226c28dda934fa6020841e0' 
  AND token = 'evz7smWbelZv4kwCokmva9n4zMjJHCcnha2eo8Z3AxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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