SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb727790d21d88f70eb5c49babb91ff7506f8e90c4a330e22e3311a58a182f6' 
  AND token = '2U3oA7gMlTC9EL1TyaPq+Ddg5UQUJREOc6wp2VKuZAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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