SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2583ba6ac7ff5549af578933472eb3c3f0e0e91397ad4a94086b69869bdde64c' 
  AND token = 'oQGqaB5NiaKoHvQooL9f2G0tB/jdYZVprzZe0QSXM6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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