SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e99760f3541c84504964107dd3f3e73e0f973f4499feda1d0660b8410528fa84' 
  AND token = 'YrnxguoLBILV5n9fyTBCrRTP56Tgf1g1i1kBCQ9qfos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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