SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '369c2e811b2bb7e0ad10d15e191e0b64c5f47a2f41b828a9da9a9ff7a63cf22a' 
  AND token = 'Kkkn3rjf+/RZxg3DbiZtE+0KyWx9D//dEf85NCLJzbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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