SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f29af5b6551bd20d0a176db518e63545d07f90126607d00ef9507f2c9ddff3f0' 
  AND token = 'OWEM31nRoBLmZksa0vg8fjbvenzdOVMAFgMXWjRJaKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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