SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfae49126dab5d05a07d79cec5e5f23326911aedca91d4b643bce83dd0740aca' 
  AND token = 'AXap1rmTGtGrLpFiJHTwA1dQsA5GnfTqGZd7AOHsUfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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