SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d49346a98113603b35cd072e9ec2179c112a575b9d5f60c9756afa49f4fbd43' 
  AND token = 'CaS/uWfzrDWxIxFWCdrh7EzCqVMiws/TNC75NnAVr0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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