SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a1b150b9704fc6ea0a8fbeec8fb8063f1a2427483510c71dc3c65ada002cee7' 
  AND token = 'X/kRgkBijxCNJrzY1AV2vGmM5S6BEXDBe5TuAkGrE8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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