SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0351af5a0871a474bfe9a907c1cafeb3f5486ace42164005c5d811d509cf0a2b' 
  AND token = 'AKxBzXLnx9sVaPiZvlYHGtfkNJcEWJYwcizYPPFLJRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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