SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25dafd7fdd1c39eb2f358ed5348b4765b04c2aebd8660a2f1f45474b0f81f407' 
  AND token = 'wF+1Ws16gBG+VzF9S7udzurCW3WYFvm2ckF7Q6BeCKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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