SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '645b9ef7bc5261fe813ced9bb8d3fe088aaff99c702885bffeb3452ed47f4b51' 
  AND token = 'e/idQP6Qf5/pMyCT9wKMOS63SiR8yLFYBccDfJjhMKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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