SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4187aa6449d635c89e57ff9de32319ed39eba894a93af1d5bccbd5c1415b819' 
  AND token = 'JxMn2U3IyqgkfbIhweiQ1W4SY4c5AWbMkclYsQmXT9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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