SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29039b784f86409a416505d59ecd0f64690a3e9596b02ddc7491d838adebc7d6' 
  AND token = 'aNyuvFrD/MI5uKn0gL3lCWer6WtPFQVkCJhxm6YeBqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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