SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8751266a2a1ac9bf1179806e0d2a99623b11fbc0ad1251bb741d79bb4b4a7a4a' 
  AND token = 'cc2gnoA/tfYn7pplM+BYkMeMa1F4FJIlGfnRJ55jecg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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