SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f3414945e33a0a41a546164c2f3090f7334c03bdfad656ad8e8ab06f092cce9' 
  AND token = 'SmRs98wzEtEuaNfxDnKpypY2nBPEvjgCLS+pZ2rKM/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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