SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4063032e01307cc2d6ff8ad806911464002a1e91e6e304dc9ac3421b404742d' 
  AND token = 'CHYYMdLUZoV/wBpN3+Rxs1DW5vUu9LdrfzaDKIHDTLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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