SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3900caeb79716b775c78b201fe23e06427889688854687c8ed0ac32b2181ec49' 
  AND token = 'g8gpBhnNnEhr8tAYi+JCFf5+ZqtDyu56jU4ZMpS0PPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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