SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdf2c2b476b0d0f0f033995016c3616a27ce0d07986db029b9e14a51b8bb3e04' 
  AND token = 'nqVYJcqP1vqqDeTHGjuhws9TLKBpwpZqjL0PaiuoPrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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