SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102c32613a7cb9479578148d01c4822b28bb100a4fd8eb4b5a0f255fc31af4c1' 
  AND token = 'HB1UUEL3w78tRRc8fEIxpMMkvCD91l0vw5O369Aawxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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