SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71a23ca087c5ed6610b1a1808e7d6d9d1cfff29467ef4d25ede3fd6841e11edf' 
  AND token = 'uctxJisSJOSlzltPvEpshvWM8HFH4b5RCtWEG5Q8Rzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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