SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ed5608db0303eb3d1d7bfe63026c02f0c47d0a307d04798cae051e46780f91f3' 
  AND token = '2U4wEqs+BPDHEvRTtTDSqThqoM6YUY4fHQNxzjUuZAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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