SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e60ef448d1bae5f293e2c3d27400f99a9e82352f79e92ed898acba5c768e731' 
  AND token = 'tbkvlBQ2inxbcyzPoze23PkHJus+ty9IOvIifzrsPB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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