SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43a2653fc91ca40a3fd318a630535315eecc20ed3a03ecc8fcb7ad391368c6d0' 
  AND token = 'Qe0FtYwg+DCYVoQ/he+eCpyUut44ULkzm3zTHWnkbOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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