SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd693c072b2d798b0e150dbbbdaad508090955dd15888ba5dcc1b7b98018ac426' 
  AND token = 'szuKQMUNK7u5f4mntkbZbvKr6/5k+7qsccqzPL2wVNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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