SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2096ad47235ed590ef2548a0bf90a175899378bba2be87f36106784d85fe71df' 
  AND token = 'B+wNI+U1A+bdhNBIyprE/3GrDc3efGyD6zYYcD/BuE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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