SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '581f94318fc967752bd227fd2713b16fba9b71a65f5666e7771a0d42fcc3847b' 
  AND token = 'hHVARUUznwAYvPEYdxavYFQ4kVk9yTgqOH/TpBmyGQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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