SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a018531e3b3fe50752807e0c8fe011106859bd7983cb9a5a61cdcdee280fb57a' 
  AND token = '9q1+wRPwALk+XZVYu4L5DNkXDtS8G6loVfT0+Dkax78=' 
  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"
    }
  }
}