SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1154030909a6942aa878765133a9024355af954743d1043a50fd444e709fd812' 
  AND token = 'rT9vBGHlNc1Vh4PNduCHkN5XyWBvA24oWaqbVe03lCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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