SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94d76be384de3743c67dfa694260d3708281fd98da56041a8f930781e68be869' 
  AND token = 'FxsbpPe8qQAeleyQefPAsRcvvHQ9uPsDppHyLAXlfaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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