SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e3256ffa787f0d4b9a7a94a83972aaa5d37d2e017b2ba82926f17db881a71df' 
  AND token = 'ZP05Nuaf4tngZ5akoJnOQzJIbJWalkJ8FM2jkcQZKws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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