SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4820ff14b28507b97d3a4333c009b8d2aafd3f0b37ce22276197af25cea22c11' 
  AND token = 'tehl+PsrpsYGAvTYzcXykew/LK7TXKYQAxJ+FzuesPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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