SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e25b1bbafbc10243100d458741c168c1f7696ae8f6d6ab9955ff3122075abce9' 
  AND token = 'PHVR/rSk0jY3rmgPobh7vpdDVH8uYHyZHJ17gGzr7zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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