SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2736ab56c14ae60c981858564674e5d4ec224f88272288a8057c058506411a07' 
  AND token = 'A2qsssxT8j6xdy30PcCaFPUmWtNUk9bZGOYgkNM0H1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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