SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c00b18d8daaa6ccfaa65eea86f86fdde1070d94b37ee41eea628beaae07b4377' 
  AND token = 'pEi2iKNoTxMDnHowUgZde/7YkmNC4Cu0JqAU7Me8EvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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