SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a538d0096691b40b001abf2767e118734baa5b758bb472a0394084139116016' 
  AND token = 'nXhwVx+oAqk2/x9oc8uJAzWImX2gYmdMcy7/CMbdMVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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