SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cbbd270f3ec109d559ab8994da704b25c0ba794aba94626bb71499be903238e' 
  AND token = 'JR/c76N3Z5JpucR0GPS+JHXpbtE1Uc2bmwPV6mXLWCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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