SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f7a14c8781430ff3be75463362ceb4d6e321f993f2140da4eb6fe0bf1d3217b' 
  AND token = 'D4JUH4e050+1AWTdu5Wv0K1JuZiSiU0HmNAudb9gUo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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