SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f19e6f331386160de79df7efa06133eb901b126cdce38bfcec9f633c1068ecc2' 
  AND token = 'qlqOLW0kqagYfCzQy9Jfy7eoYft13dHD1lohVnXM7bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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