SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8771fb0d1c491852c0519b12be7b1142cf1a8317777220aaf6e78a0fc529d51' 
  AND token = 'OtZzhL0JTjFOdqHKIS9UqIhxXpMY7/6/WJZRodIawAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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