SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '066fa1749136585aa2957e9a4cbc6bbc4247d6642855a5f35dd309657dc771b0' 
  AND token = 'HQQLahe86yzIBTSpaTOT8YNdUs/nH3vn5p4ltgbhVPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}