SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f946d2c12b5353e1370dec3dfa2c7db9c94c27d74cdf588f68d45be86c473c5' 
  AND token = 'RgY+zihCop2hq01KASEGsQkuZWVBY803mpb3C1vLmZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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