SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11cff1a5711153aaf56cb2fd471da220786c9252f023b1dbd0001e555bd08f41' 
  AND token = 'RP4F/ahzFHn8FSW9HAlmuq5jiEgw3xUzjBZJ9yL20Vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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