SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d90a871591c4021db86f3a1a7182e68f2ee7432558974dbf45c8ef6b6e847a' 
  AND token = 'd6VM3jWOxhTFmGkwUZtvcj+ipnEwvsUeB57vDfBeqbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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